Thanks for that reply Interitus. That helps a lot for my decision. Although I probably won't use crossfire anyway, does that mean the gigabyte P55 boards won't be much of a performance hit in crossfire?
Well if the rumors are true, then SLI/CF gets disabled when USB3/SATA3 are on. In that case it takes the PCIe lanes completely out of the equation since SLI/CF is just "disabled" altogether. However in terms of just SLI/CF without SATA3/USB3 enabled, I'm sure that the P55 boards are fine for SLI/CF. I would imagine the only cards that would really start to see diminishing results would be the multi-core on single PCB cards like the 4870x2 or the GTX295. Don't quote me on that, I have no evidence to back it up.
Basically what you're looking at with this board is one of 2 scenarios:
1) You use SATA3/USB3 and wind up with a single card in an x8 bandwidth slot
or
2) You don't use SATA3/USB3 and you get one x16 or 2 x8 slots.
This is a big reason why I *might* decide to hold off for X58 boards with USB3/SATA3. Even if they have to cough up some PCIe lanes, they've got more than enough for this solution and SLI as well. I still don't understand how the Asus solution is any different. I would imagine it still has to use some PCIe lanes to get the bandwidth it needs. There's just not enough lanes on P55 to have the best of both worlds.